The present invention relates to a device comprising a fluid distributor which has at least one flow duct with an inlet opening and an outlet opening, wherein the inlet opening can be connected to a supply line for a fluid, and means for moving the fluid distributor are provided. Devices of this type can be used, for example, for cleaning boilers of a combustion system. Furthermore, the invention also relates to a method for operation of a boiler with a throughflow of flue gas using such a device.
In connection with the operation of combustion systems, it is of particular interest to obtain a high degree of efficiency for the energy conversion. For this purpose, the hot flue gas is guided past a plurality of heat exchangers such that the heat is transmitted to a heat exchange medium, in particular water, flowing in the heat exchangers. However, when the hot flue gas makes contact with said heat exchangers, impurities, soot and the like remain stuck thereto and over the medium term obstruct the transfer of heat from the flue gas to the heat exchange medium. It is therefore necessary to free the heat exchangers at predetermined intervals from said impurities.
To clean said heat exchange surfaces or else the boiler wall use is made, for example, of cleaning appliances as described, for example, in WO 96/38704. A cleaning appliance of space-saving construction is also revealed in EP 1 259 762 B1.
Said cleaning appliance, in particular a “water lance blower”, has a water lance with which a bunched water jet can be discharged through the boiler chamber onto an opposite wall or onto a heat exchanger, with the impurities adhering there being removed as a result. Cleaning in this way can take place during the operation of the combustion system. In order to carry out this cleaning process, the impact region of the water jet, also referred to as the blowing pattern, is guided along a predetermined path on the surface to be cleaned. The path generally runs in a meandering manner and specifically avoids obstacles, openings or other sensitive zones in the cleaning region. Owing to the kinetic energy of the water jet and to the abrupt evaporation of water which has penetrated the pores of the deposits, a flaking-off of the dirt consisting of soot, slag and ash is brought about.
Furthermore, it is known to use diverse sensor arrangements to check and to monitor the soiling of the heat exchange surfaces or of the boiler wall and then to undertake specific cleaning. For example, DE 196 40 337 reveals a method for assessing and cleaning off coatings of slag on a heating surface, wherein the temperature of the heat exchange method is measured at selected pipes of the heating surface in the interior of a steam boiler. This measured temperature is compared with a reference temperature of a clean heating surface. As a result of this comparison, it can then be decided whether the transfer of heat is still sufficient or whether cleaning has to be carried out. Furthermore, DE 196 05 287 reveals a method and a system for controlling the running time of a boiler. In this case, it is also proposed that it is expedient, in order to generate further information about the deposition mechanism or ash particles flowing past, to record and to analyze the temperature distribution of the environment of the deposit. It is possible in this connection to identify, for example, hot ash particles which may result in caking upstream on the boiler wall or on the internal components. In order to record information of this type, it is proposed to provide a deposition sensor, for example a CCD camera, which projects into the boiler.
A selective cleaning method which is particularly effective and can be carried out in a simple manner is also revealed in DD 281452 B5 in which the boiler walls which are to be cleaned are divided into separate surfaces and are monitored. Cleaning processes for said separate surfaces are initiated specifically only when predetermined characteristic values are reached.
Further methods for monitoring the operating parameters of the combustion or for monitoring the deposits in the interior of the boiler are “thermography”, “sound pyrometry” or “infrared pyrometry”. With the aid of such measured value recording systems, information about the temperature of objects in the interior of the boiler, about the temperature of the flue gas, about the flow velocity of the flue gas, about adhering impurities, etc. can be determined.